1. Technical Field
The present disclosure relates to power transmitting apparatuses for arbitrarily and selectively transmitting or cutting off the driving power of an engine to or from wheels of a vehicle.
2. Description of the Related Art
In a conventional power transmitting apparatus (e.g., automatic transmission) of a vehicle, an automatic power transmitting apparatus can be provided with a torque converter (e.g., so-called “torque converter type” starting system) or with a starting clutch (e.g., so-called “start-clutch type” starting system). In the automatic power transmitting apparatus of the torque converter type, it is possible to improve the starting performance at the time of start due to the torque amplification function of the torque converter. On the other hand, in the automatic power transmitting apparatus of the start-clutch type, it is possible to improve the power transmitting efficiency since it does not have slippage during the steady running of vehicle which would be caused by the apparatus of the torque converter type.
As described above, in the automatic transmission of the torque converter type, although it has a technological advantage of improvement of the starting performance at the time of start due to the torque amplification function of the torque converter, it has a technological disadvantage of reduction of the power transmitting efficiency due to slippage of the torque converter. On the other hand, in the automatic transmission of the start-clutch type, although it has a technological advantage of improvement of the power transmitting efficiency during the steady running of vehicle since it does not have slippage peculiar to the torque converter type, it has a technological disadvantage of reduction of the starting performance since it does not have the torque amplifying function of the torque converter at the time of start and thus it is necessary to increase the reduction ratio of the transmission to prevent reduction of the starting performance.
In order to solve these defects of the prior art, there has been proposed in Japanese Patent Document JP 2010-84828 A a power transmitting apparatus which is provided with a clutch means for switching between a first power transmitting system for transmitting the driving power of the engine to wheels via a torque converter and a second power transmitting system for transmitting the driving power of the engine to wheels without use of a torque converter and is able to satisfy both functions of improving the starting performance due to the torque amplifying function of the torque converter and of improving the power transmitting efficiency during the steady running of vehicle. In such a power transmitting apparatus of the prior art, it is possible to damp torque variation during transmission of the driving power of the engine by using a damper having a predetermined spring property disposed in the power transmission path of the second power transmitting system when the apparatus has been switched to the second power transmitting system by a clutch means.